Camera and method of controlling operation of same

ABSTRACT

It is arranged so that a camera user can recognize presence of camera shake in a case where the user is looking at a subject through an optical viewfinder. A portion of the image of a subject captured by a solid-state electronic image sensing device is displayed in an electronic viewfinder constituted by a liquid crystal display unit. An image of a subject optically formed via an objective window of the optical viewfinder and the portion of the image of the subject displayed in the electronic viewfinder are superimposed. If camera shake is taking place, the portion of the image of the subject in the superimposed images will appear blurry. By viewing this portion of the image of the subject, therefore, the user can tell whether camera shake is taking place.

CROSS-REFERENCE TO RELATES APPLICATIONS

This application is a Continuation of PCT International Application No.PCT JP2013/064348 filed on May 23, 2013, which claims priority under 35U.S.C. §119(a) to Japanese Patent Application No. 2012-146944 filed Jun.29, 2012. Each of the above application is hereby expressly incorporatedby reference, in its entirety, into the present application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a camera and to a method of controlling theoperation thereof.

2. Description of the Related Art

There are instances where a camera is formed to include an opticalviewfinder having an objective window facing the subject and an eyepiecewindow looked at by the user. The user decides the angle of view andtakes a picture while looking at the optical viewfinder of the camera.

A finder unit implemented in the art makes it possible to display suchinformation as a visual-field frame, which is displayed on the displayscreen of a liquid crystal display unit, by superimposing thisinformation upon the optical image of a subject that can be seen byusing an optical viewfinder (Patent Document 1). There is also a camerain which the image of a subject obtained from an optical viewfinder andthe image of a subject obtained from a solid-state electronic imagesensing device are displayed in separate areas within a finder (PatentDocument 2).

Patent Document 1: Japanese Patent Application Laid-Open No. 2012-65294

Patent Document 2: Japanese Patent Application Laid-Open No. 2008-244511

When a camera is being shaken, the image of the subject captured byimaging will be blurred by such shaking motion. Nevertheless, there areinstances where the user cannot tell that the captured image of thesubject is blurred due to shaking merely by looking at the subjectthrough the optical viewfinder. Consequently, even though the subjectbeing viewed by the user may not be blurred, the image of the subjectcaptured will be blurred. In Patent Documents 1 and 2 as well, the usercannot tell that the image of a subject affected by camera shake is insuch a condition.

SUMMARY OF THE INVENTION

An object of the present invention is to arrange it so that even if auser is looking at a subject through an optical viewfinder, the user canascertain the condition of the image of the subject that will becaptured when the camera sustains camera shake.

According to the present invention, there is provided a cameracomprising: an optical viewfinder formed on the front of the camera andhaving an objective window facing a subject and an eyepiece window forlooking at the subject seen through the objective window; a solid-stateelectronic image sensing device for imaging the subject and outputtingimage data representing the image of the subject; a display unit fordisplaying a portion of the image of the subject, which is representedby the image data that has been output from the solid-state electronicimage sensing device, on a display screen; and a deflecting unit forintroducing the portion of the image of the subject, which is beingdisplayed on the display screen of the display unit, to the eyepiecewindow so as to be superimposed upon the subject seen through theeyepiece window.

The present invention also provides an operation control method suitedto the above-described camera. Specifically, the present inventionprovides a method of controlling operation of a camera which includes anoptical viewfinder formed on the front of the camera and having anobjective window facing a subject and an eyepiece window for looking atthe subject seen through the objective window, the method comprisingsteps of: a solid-state electronic image sensing device imaging thesubject and outputting image data representing the image of the subject;a display unit displaying a portion of the image of the subject, whichis represented by the image data that has been output from thesolid-state electronic image sensing device, on a display screen; and adeflecting unit introducing the portion of the image of the subject,which is being displayed on the display screen of the display unit, tothe eyepiece window so as to be superimposed upon the subject seenthrough the eyepiece window.

In accordance with the present invention, a portion of the image of asubject captured by a solid-state electronic image sensing device isdisplayed on the display screen of a display unit. A portion of thedisplayed image of the subject is introduced to the eyepiece window ofan optical viewfinder so as to be superimposed upon the optical image ofthe subject seen through the eyepiece window. Since the portion of theimage of the subject captured by the solid-state electronic imagesensing device is superimposed upon the optical image of the subjectseen through the eyepiece window of the optical viewfinder, the user, byobserving the superimposed state, can tell whether the captured image ofthe subject is blurry due to camera shake. Further, since what issuperimposed on the optical image of the subject seen through theeyepiece window of the optical viewfinder is a portion of the capturedimage of the subject, the user can check the subject based upon theremaining portion of the image of the subject and can decide the angleof view.

The apparatus may further comprise a camera-shake detection device(camera-shake detection means) for detecting shaking of the camera; anda camera-shake notification device (camera-shake notification means) fornotifying of camera shake in response to the fact that camera shake hasbeen detected by the camera-shake detection device.

By way of example, the camera-shake notification device notifies ofcamera shake by displaying, on the display screen of the display unit, acharacter string to the effect that camera shake is taking place or animage representing the fact that camera shake is taking place, or bychanging the form of a border, which encloses a portion of the image ofthe subject, in accordance with whether or not camera shake is takingplace.

In a case where a principal subject seen through the optical viewfinderand a principal subject image among subject images captured in thesolid-state electronic image sensing device are displayed on the displayscreen of the display unit, the display unit may display a portion ofthe subject image on the display screen upon applying a parallaxcorrection in such a manner that the principal subject image and theprincipal subject will coincide.

If the distance from the camera to the principal subject is equal to orgreater than a predetermined distance, the display unit may, in a casewhere a principal subject seen through the optical viewfinder and aprincipal subject image among subject images captured in the solid-stateelectronic image sensing device are displayed on the display screen ofthe display unit, display a portion of the subject image on the displayscreen in such a manner that the principal subject image and theprincipal subject will coincide.

The apparatus may further comprise a recording control device (recordingcontrol means) for recording image data, which has been output from thesolid-state electronic image sensing device, on a recording medium.

Other features and advantages of the present invention will be apparentfrom the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a digital camera;

FIG. 2 is a back view of the digital camera;

FIG. 3 is a perspective view of the digital camera when viewed from theback;

FIG. 4 is a block diagram illustrating the electrical configuration ofthe digital camera;

FIG. 5 illustrates the positional relationship between a lens barrel andan optical viewfinder;

FIG. 6 illustrates a parallax angle between the lens barrel and theoptical viewfinder;

FIG. 7 illustrates the structure of an optical viewfinder;

FIG. 8 illustrates the relationship between a digital camera and aprincipal subject;

FIG. 9 shows an optical image of a subject and an image displayed in anelectronic viewfinder;

FIG. 10 illustrates an image obtained by superimposing an optical imageof a subject and an image displayed in an electronic viewfinder;

FIG. 11 is an image displayed in an electronic viewfinder;

FIG. 12 illustrates an image obtained by superimposing an optical imageof a subject and an image displayed in an electronic viewfinder;

FIGS. 13 and 14 are flowcharts illustrating processing executed by adigital camera;

FIG. 15 illustrates an image displayed in an electronic viewfinder;

FIG. 16 illustrates an image obtained by superimposing an optical imageof a subject and an image displayed in an electronic viewfinder;

FIG. 17 illustrates an image displayed in an electronic viewfinder;

FIG. 18 illustrates an image obtained by superimposing an optical imageof a subject and an image displayed in an electronic viewfinder;

FIG. 19 illustrates an image displayed in an electronic viewfinder; and

FIG. 20 illustrates an image obtained by superimposing an optical imageof a subject and an image displayed in an electronic viewfinder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 3, which illustrate an embodiment of the present invention,show the external appearance of a digital camera 1. FIG. 1 is a frontview, FIG. 2 a back view and FIG. 3 a perspective view when viewed fromthe back.

With reference to FIG. 1, a lens barrel 2 projects forwardly from theapproximate center of the front side of the digital camera 1. An opticalviewfinder is constructed at the upper right of the digital camera 1 andis formed to include an objective window 3 facing a subject. A flashdevice 4 is provided on the left side of the objective window 3.

A shutter-speed dial 6, a power lever 7, a shutter-release button 8 andan exposure dial 9 are provided on the top of the digital camera 1 onthe left side thereof when viewed from the front. The shutter-speed dial6 is a circular dial that is free to rotate. By rotating theshutter-speed dial 6, the user can set a desired shutter speed. Thepower lever 7 can be moved through a prescribed angle rightward andleftward as seen from the front. By moving the power lever 7 through theprescribed angle, the user can turn the power supply of the digitalcamera 1 on and off. The power lever 7 has the shape of a ring with aninterior space when viewed from the top (see FIG. 3), and theshutter-release button 8 is provided within the space. The exposure dial9 also is a circular dial that is free to rotate. By turning theexposure dial 9, the user can correct the exposure.

With reference to FIGS. 2 and 3, a liquid crystal display device 12 isprovided on the back side of the digital camera 1 substantially over theentirety thereof. An eyepiece window 11 constituting the above-mentionedoptical viewfinder is formed on the back side of the digital camera 1 atthe upper left thereof. A command lever 10 movable to the left and rightis provided on the back side of the digital camera 1 at the upper rightthereof. By manipulating the command lever 10, the user can supply thedigital camera 1 with a command such as an aperture adjustment commandin steps of ⅓ EV when the camera is in the manual exposure mode.

Provided below the command lever 10 are an AF (autofocus)/AB(autoexposure) lock button 13, a command dial 14, a menu/OK button 15, aback button 16 and a RAW button 17, etc.

With reference primarily to FIG. 3, the shutter-speed dial 6, powerlever 7, shutter-release button 8 and exposure dial 9 are provided onthe top of the digital camera 1 on the right side thereof (the rightside when viewed from the back), as mentioned above. The power lever 7is formed to have a projection 7A projecting toward the front side. Thepower supply of the digital camera 1 can be turned on and off bygrasping the projection 7A and moving it to the right or left.

By bringing an eye close to the eyepiece window 11 of the opticalviewfinder and looking at the eyepiece window 11, the user can view asubject through the objective window 3 and eyepiece window 11 and candecide the camera angle.

FIG. 4 is a block diagram illustrating the electrical configuration ofthe digital camera 1.

The overall operation of the digital camera 1 is controlled by a CPU 20.

As mentioned above, the digital camera 1 is provided with operatingswitches 23 such as the shutter-speed dial 6, power lever 7 and exposuredial 9. Signals from the operating switches 23 are input to the CPU 20.Further, a signal indicating whether the power supply has been turned onor off by the power lever 7 also is input to the CPU 20. A changeoversignal from a changeover switch 21 for switching between a shooting modeand a playback mode also is input to the CPU 20.

The digital camera 1 includes a solid-state electronic image sensingdevice 34. A zoom lens 31, iris 32 and focusing lens 33 are provided infront of the solid-state electronic image sensing device 34. The zoomlens 31 has its amount of zoom controlled by a motor driver 37, the iris32 has its aperture value controlled by a motor driver 38, and thefocusing lens 33 has its focus position controlled by a motor driver 39.

When the image of a subject is formed on the photoreceptor surface ofthe solid-state electronic image sensing device 34, the solid-stateelectronic image sensing device 34 is controlled by a timing generator40 and a video signal representing the image of the subject is outputfrom the solid-state electronic image sensing device 34. The videosignal that has been output from the solid-state electronic imagesensing device 34 is subjected to correlated double sampling in a CDS(Correlated Double Sampling) amplifier circuit 35. The CDS amplifiercircuit 35 outputs the resultant video signal, which is converted todigital image data in an analog/digital conversion circuit 36.

The digital image data is input to an AF (autofocus) detection circuit46 via an image input controller 41. A focusing control signal isgenerated based upon the entered digital image data, and the focusingcontrol signal generated is input to the CPU 20. The motor driver 39 iscontrolled based upon the focusing control signal so that the focusinglens 33 is positioned. The AF detection circuit 46 also calculates thedistance to a principal subject specified by a AF target frame 94,described later. If necessary, the digital camera 1 would be providedwith a rangefinding device for measuring the distance to the principalsubject. Further, the digital image data that has been output from theimage input controller 41 is input to an AE (autoexposure)/AWB(automatic white balance) 47 as well. The AE/AWB detection circuit 47generates an exposure control signal and a white balance adjustmentsignal. The exposure control signal generated is input to the CPU 20.The motor driver 38 is controlled based upon the exposure controlsignal, whereby the aperture value of the iris 32 is controlled.Further, the white balance adjustment signal generated in the AE/AWBdetection circuit 47 is input to an image signal processing circuit 42.Image data that has been output from image input controller 41 also isinput to the image signal processing circuit 42 as well. The imagesignal processing circuit 42 subjects the image data to a white balanceadjustment based upon the white balance adjustment signal.

Image data that has been output from the image signal processing circuit42 is applied to a liquid crystal display device 12 via a video encoder44. The captured image of the subject is displayed on the display screenof the liquid crystal display device 12.

As mentioned above, the digital camera includes an optical viewfinder60.

The optical viewfinder 60 has an eyepiece lens 66 provided in front ofthe eyepiece window 11. A prism 63 formed to have a half-mirror 64 isprovided in front of the eyepiece lens 66. The half-mirror 64 is formedso as to have a 45-degree angle of incidence with respect to opticalaxis C3 of the optical viewfinder 60. An OVF (optical viewfinder)shutter (which may be a mechanical shutter or a liquid crystal shutter)62 and an objective lens 61 are provided in front of the prism 63. Theoptical viewfinder 60 is further provided with an electronic viewfinder65. Data representing various information and the like that are outputfrom the video encoder 44 are input to the electronic viewfinder 65,where this information and the like are displayed. By inputting imagedata, which has been obtained by imaging, to the electronic viewfinder65 when the OVF shutter 62 has closed, the image of the subject obtainedby imaging is displayed on the display screen of the electronicviewfinder 65.

When the OVF shutter 62 is open, the image of a subject OB formed by theobjective lens 61 and eyepiece lens 66 can be seen through the eyepiecewindow 11. Further, when various information is displayed on the displayscreen of the electronic viewfinder 65 when the OVF shutter 62 is open,light rays representing this information are reflected by thehalf-mirror 64 so that the user can see the information. Information andthe like displayed on the display screen of the electronic viewfinder 65can be seen upon being superimposed upon the optical image of thesubject formed by the objective lens 61, etc.

In particular, according to this embodiment, a portion of the image ofthe subject captured by the solid-state electronic image sensing device34 can be displayed in a portion of the electronic viewfinder 65 in astate in which the OVF shutter 62 is open. The portion of the image ofthe subject displayed in the electronic viewfinder 65 is superimposedupon the optical image of the subject seen through the objective window3. If camera shake is non-existent, the portion in the electronicviewfinder and the optical image of the subject seen through theobjective window 3 should not be offset from each other, but they willbe offset if camera shake occurs. By observing the state of overlap, theuser can tell whether camera shake is present or not.

An eye sensor 67 is mounted in the vicinity of the eyepiece window 11.The eye sensor 67 detects that the eye of user has been brought near theeyepiece window 11, whereupon the OVF shutter 62 opens so that theoptical image of the subject OB can be viewed through the eyepiecewindow 11. If the eye sensor 67 has not detected that the eye of theuser has been brought near the eyepiece window 11, the OVF shutter 62closes. The image of the subject is displayed on the liquid crystaldisplay device 12 and the user decides the camera angle while viewingthe image of the subject being displayed on the liquid crystal displaydevice 11. Even if the eye sensor 67 has detected that the eye of theuser has been brought near the eyepiece window 11, the OVF shutter 62can be turned off, image data representing the image of the subject canbe input to the electronic viewfinder 65, and the image of the subjectdisplayed in the electronic viewfinder 65 can be viewed through theeyepiece window 11.

The digital camera 1 further includes such circuits as a face detectioncircuit 48, a moving-body detection circuit 49 and a camera-shakedetection circuit 55. The camera-shake detection circuit 55 is s circuitfor detecting whether the digital camera 1 is experiencing camera shake.

When the shutter-release button 8 is pressed, image data that has beenoutput from the image signal processing circuit 42 as described above isstored temporarily in a memory 50. The image data is read out of thememory 50 and is input to a compression processing circuit 43, whichproceeds to execute prescribed compression processing. The compressedimage data is applied to and stored temporarily in the memory 50. Thecompressed image data is read out of the memory 50 and is recorded on amemory card 52 by a memory card controller 51.

When the playback mode is set, image data that has been recorded on thememory card 52 is read out and the image represented by the read imagedata is displayed on the display screen of the liquid crystal displaydevice 12.

Furthermore, image data representing information displayed in theelectronic viewfinder 65 and data representing various information alsohave been stored in the memory 50. By reading out these items of dataand applying them to the electronic viewfinder 65 via the video encoder44, various information is displayed on the display screen of theelectronic viewfinder 65.

FIG. 5 illustrates the relationship between the lens barrel 2 and theobjective window 3 when the digital camera 1 is viewed from the front.

The lens barrel 2 has an optical axis C2. The optical axis C2 and theoptical axis C3 of the optical viewfinder 60 (objective window 3) are adistance d apart and parallax exists between them. Consequently, thereare instances where an offset develops between the optical image seenthrough the eyepiece window 11 and the image of the subject captured bythe lens barrel 2. As described above, when a portion of the image ofthe subject captured by the solid-state electronic image sensing device34 is displayed in the electronic viewfinder 65 and this is superimposedupon the optical image of the subject formed via the objective window 3,there are instances where, owing to the aforesaid parallax, the portionof the image of the subject displayed in the electronic viewfinder 65and the optical image of the subject will not coincide even if camerashake is non-existent. In this embodiment, therefore, if camera shake isnon-existent, then a parallax correction is applied as necessary in sucha manner that the portion of the image of the subject displayed in theelectronic viewfinder 65 and the optical image of the subject willcoincide.

FIG. 6 illustrates a case where principal subject OB is seen (imaged)via the lens barrel 2 and how the subject OB is seen through theeyepiece window 11 of the optical viewfinder 60.

As mentioned above, the distance between the optical axis C2 of the lensbarrel 2 and the optical axis C3 of the eyepiece window 11 is d. Let Drepresent the distance from the lens barrel 2 to the principal subjectOB. Accordingly, a parallax angle θ defined by a line from the lensbarrel 2 to the object OB and a line from the eyepiece window 11 to theobject OB is θ=arctan(d/D). That is, in a case where the principalsubject OB is viewed through the lens barrel 2, the principal subject OBthat appears in front can be seen from the eyepiece window 11 with anoffset equivalent to the parallax angle θ.

FIG. 7 illustrates the structure of the optical viewfinder 60. Thediagram at the top of FIG. 7 illustrates the optical viewfinder 60 in aplanar view in a manner similar to FIG. 4, and the diagram at the bottomof FIG. 7 illustrates the optical viewfinder 60 in three dimensions.Components FIG. 7 identical with those shown in FIG. 4 are designated bylike reference characters.

As shown in FIG. 6, when the principal subject OB is viewed through theeyepiece window 11, it is offset from the optical axis of the opticalviewfinder 60 by the parallax angle θ. Therefore, in order to make theportion of the image of the subject displayed in the electronicviewfinder 65 coincide with the optical image of the subject formedthrough the objective window 3, the portion of the image of the subjectneed only be displayed upon being offset by the parallax angle θ. Itgoes without saying that the direction in which the portion of the imageof the subject is offset through the above-mentioned angle is decided inaccordance with the positional relationship between the positions wherethe eyepiece window 11 and lens barrel 2 are placed and the positionwhere the optical viewfinder 60 is placed.

FIG. 8 illustrates the positional relationship among the digital camera1 and principal subjects OB1, OB2 and OB3 as viewed in a plane.

If the principal subject OB1 is at a position comparatively far from thedigital camera 1, then a parallax angle formed with the optical axis ofthe objective window 3 will be θ1 in a case where the principal subjectOB1 is viewed from the eyepiece window 11. Similarly, if the principalsubject OB2 is at an intermediate position that is neither far from norclose to the digital camera 1, then a parallax angle formed with theoptical axis of the objective window 3 will be θ2 in a case where theprincipal subject OB2 is viewed from the eyepiece window 11.Furthermore, if the principal subject OB3 is at a position close to thedigital camera 1, then a parallax angle formed with the optical axis ofthe objective window 3 will be θ3 in a case where the principal subjectOB3 is viewed from the eyepiece window 11. These parallax angles θ1, θ2and θ3 are related as follows: θ1<θ2<θ3. Since the parallax angle willbe small if the distance from the digital camera 1 is great, as is thecase with the principal subject OB1, there will be almost no offsetbetween the optical image of the subject seen through the objectivewindow 3 and the portion of the image of the subject displayed in theelectronic viewfinder 65, as mentioned above. This means that theabove-mentioned parallax correction need not necessarily be applied in acase where the distance from the digital camera 1 is great, as is thecase with the principal subject OB1.

Shown at the top of FIG. 9 is an example of a subject image 85 formedoptically through the objective window 3.

When the eye of the user is brought near the eyepiece window 11 and theOVF shutter 62 opens, the user sees the optical subject image 85 formedby the objective lens 61 and eyepiece lens 66.

Shown at the bottom of FIG. 9 is an example of an image 88 displayed inthe electronic viewfinder 65.

When the eye of the user is brought near the eyepiece window 11 and thisis sensed by the eye sensor 67, the image 88 shown at the bottom of FIG.9 is displayed on the display screen of the electronic viewfinder 65.

A visual-field frame 90 indicating a picture-taking zone is formed onthe image 88.

An area occupying about one-third of the visual-field frame 90 on theright side thereof is delimited as a confirmation display area 89. Aportion of the image of the subject captured by the solid-stateelectronic image sensing device 34 in the manner described above isbeing displayed in the confirmation display area 89. In the exampleshown at the bottom of FIG. 9, the portion of the image of the subjectcaptured by the solid-state electronic image sensing device 34 in astate in which camera shake is taking place is being displayed in theconfirmation display area 89. The image within the confirmation displayarea 89, therefore, is blurry to due to camera shake. The image of thesubject captured by the solid-state electronic image sensing device 34is not being displayed within the visual-field frame 90 with theexception of the confirmation display area 89. The confirmation displayarea 89 is formed to have a border 89A so that the user can ascertainthat this area is the confirmation display area 89.

Numerals 92 indicating the number of photos that can be taken and acharacter 93 indicating image size are being displayed at the upperright of the visual-field frame 90. Further, an AF target mark 94 isbeing displayed at the center of the visual-field frame 90. The subjectspecified by the AF target mark 94 is a principal subject. An exposurecorrection bar 95 is being displayed at the lower left of thevisual-field frame 90. Furthermore, a depth-of-field display bar 96, acharacter 97 indicative of exposure mode, shutter speed 98, aperturevalue 99 and ISO sensitivity 100 are being displayed below thevisual-field frame 90.

FIG. 10 illustrates an image obtained by superimposing the image 88,which is displayed in the electronic viewfinder 65 shown at the bottomof FIG. 9, upon the optical image 85 shown at the top of FIG. 9.

Light rays representing the portion of the image of the subject withinthe confirmation display area 89 as well as information such as thevisual-field frame 90 displayed on the electronic viewfinder 65 reachthe eye of the user, who is looking at the eyepiece window 11, owing tothe half-mirror 64. The user, therefore, can see an image that is theresult of superimposing the information such as the visual-field frame90, which is being displayed on the electronic viewfinder 65, upon theoptical image 85 representing the image of the subject, as shown in FIG.9.

In particular, according to this embodiment, a portion of the image ofthe subject captured by the solid-state electronic image sensing device34 is displayed in the confirmation display area 89, and this portion ofthe image of the subject is superimposed upon the optical image of thesubject seen through the objective window 3. Since the image of thesubject captured by the solid-state electronic image sensing device 34will be blurred in the presence of camera shake, the portion of theimage of the subject displayed in the electronic viewfinder 65 will alsobe blurred (the image within the confirmation display area 89 is blurryalso in the example shown in FIG. 10). By viewing the portion of thesubject of the image within the confirmation display area 89, the usercan tell that camera shake is taking place.

In particular, in the area on the left side of confirmation display area89 in visual-field frame 90, the optical image of the subject formed viathe objective window 3 can be seen as is without the image of thesubject captured by the solid-state electronic image sensing device 34being displayed. Therefore, by comparing the optical image of thesubject and the image of the subject that is being displayed in theconfirmation display area 89, the user can readily ascertain camerashake if such camera shake is taking place. Further, it may be arrangedso that the border 89A of the confirmation display area 89 turns red ifcamera shake is detected by the camera-shake detection circuit 55 andturns blue if camera shake is not detected. By thus changing the form ofdisplay of the border 89A of the confirmation display area 89 inaccordance with absence or presence of camera shake, the user canreadily whether or not camera shake is taking place.

FIG. 11 is an example of the image 88 displayed in the electronicviewfinder 65. This view corresponds to the view at the top of FIG. 9.

FIG. 11 is an example of the image 88 displayed in the electronicviewfinder 65 when camera shake is not taking place. Since there is nocamera shake, the portion of the image of the subject within theconfirmation display area 89 will not be blurry.

FIG. 12 is an example of an image obtained by superimposing the image88, which is displayed in the electronic viewfinder 65 shown in FIG. 11,upon the optical image of the subject (see the view at the top of FIG.9) formed via the objective window 3. The example shown in FIG. 12corresponds to the view shown in FIG. 10.

In the example shown in FIG. 12, unlike the example of FIG. 10, camerashake is not taking place and therefore the image within theconfirmation display area 89 is not blurry. By confirming that the imagewithin the confirmation display area 89 is not blurry, the user can tellthat the image of the subject captured using the solid-state electronicimage sensing device 34 also is not blurry. For example, the border 89Ais made to turn blue.

FIG. 13 is a flowchart illustrating processing executed by the digitalcamera 1. It is assumed here that the camera has been set to the imagingmode.

When the power supply is turned on by the power lever 7 of the digitalcamera 1, whether the user is looking at the eyepiece window 11 of theoptical viewfinder 60 is checked by the eye sensor 67, as describedabove (step 71). If the eye of the user cannot be sensed by the eyesensor 67 (“NO” at step 71), it is judged that the user is not lookingat the eyepiece window 11 of the optical viewfinder 60. Consequently,the image of the subject obtained by imaging is displayed on the liquidcrystal display device 12 (step 72).

If the eye of the user is sensed by the eye sensor 67 and it is judgedthat the user is looking at the eyepiece window 11 of the opticalviewfinder 60 (“YES” at step 71), the camera is set to a sensordetection display changeover/OVF mode (step 73). The OVF shutter 62opens and the user looking at the eyepiece window 11 can see the opticalimage of the subject.

Next, it is determined whether the camera-shake detection mode has beenset by a mode setting switch (not shown) included among the operatingswitches 23 (step 74). If the camera-shake detection mode has not beenset (“NO” at step 74), a portion of the image of the subject is notdisplayed in the electronic viewfinder 65. Prescribed information suchas the visual-field frame is displayed in the electronic viewfinder 65and this information is displayed in a form superimposed upon theoptical image of the subject formed via the objective window 3 (theusual hybrid display is presented)(step 75).

If the camera-shake detection mode has been set (“YES” at step 74), AFprocessing is executed using the AF detection circuit 46 (step 76). InAF processing, the distance to a principal subject is calculated. Theparallax angle is calculated, as described above, using the calculateddistance to the principal subject and the distance from the optical axisof the lens barrel 2 to the optical axis of the objective window 3, andan amount of parallax, which is an amount of offset for shifting theportion of the image of the subject displayed in the electronicviewfinder 65, is calculated (step 77).

The portion of the image of the subject obtained by imaging is displayedin the electronic viewfinder 65 upon being shifted by the calculatedamount of parallax. The image displayed in the electronic viewfinder 65and the image of the subject formed optically via the objective window 3are superimposed in the manner shown in FIG. 10 or FIG. 12 (step 78).

If camera shake occurs (“YES” at step 79), as shown in FIG. 10, thencamera shake is detected by the camera-shake detection circuit 55 andthe border 89A of the confirmation display area 89 turns red. As aresult, the user is notified of the fact that the digital camera 1 isundergoing camera shake (step 80). If camera shake is not detected (“NO”at step 79), then the border 89A of the confirmation display area 89turns blue. As a result, the user is notified of the fact that thedigital camera 1 is not undergoing camera shake (step 81).

The processing from step 71 onward is repeated unless the power supplyis turned off or unless the mode is changed to one other than theimaging mode (step 82).

In the foregoing embodiment, amount of parallax is calculated and aparallax adjustment applied if the camera-shake mode has been set.However, a parallax adjustment need not be applied in a case where thedistance to the principal subject is equal to or greater than apredetermined distance, as mentioned above. It goes without saying thatit may be arranged so that a parallax adjustment is performed even ifthere is a long distance to the principal subject.

FIG. 14, which illustrates a modification, is a flowchart showingprocessing executed by the digital camera 1. Processing steps shown inFIG. 14 identical with those shown in FIG. 13 are designated by likestep numbers and need not be described again.

In the embodiment shown in FIG. 13, whether camera shake is taking placeor not is checked by the camera-shake detection circuit 55 and the useris notified of the absence or presence of camera shake. In theembodiment shown in FIG. 14, however, the user is not notified of theabsence or presence of camera shake. Here the user judges whether camerashake is taking place or not by observing the state of the image withinthe confirmation display area 89.

FIGS. 15 and 16 illustrate another modification.

FIG. 15, which is an example of an image 88A displayed in the electronicviewfinder 65, corresponds to the diagram at the top of FIG. 9 and toFIG. 11. Items shown in the diagram at the top of FIG. 9, etc.,identical with those shown in FIG. 15 are designated by like referencecharacters and need not be described again.

In FIG. 15, a comparatively small confirmation display area 111 isformed at the lower right of the visual-field frame 90, and theconfirmation display area 111 is formed to have a border 111A. Whereasthe confirmation display area 89 shown at the top of FIG. 9 occupiesapproximately one-third of the visual-field frame 90, the confirmationdisplay area 111 being displayed in the image 88A shown in FIG. 15 iscomparatively small. A portion of the image of the subject captured bythe solid-state electronic image sensing device 34 is thus displayed inthe comparatively small confirmation display area 111.

FIG. 16 corresponds to FIG. 10 or 12 and illustrates an image obtainedby superimposing the image 88A, which is displayed in the electronicviewfinder 65 shown in FIG. 15, upon the optical image 85 of the subjectformed via the objective window 3.

In the confirmation display area 111, the portion of the image of thesubject displayed in the electronic viewfinder 65 and captured by thesolid-state electronic image sensing device 34 is superimposed upon theoptical image 85 of the subject. If the image within the confirmationdisplay area 111 is blurry, the user can tell that camera shake istaking place.

The form of display of the border 111A of the confirmation display area111 can be changed in accordance with absence or presence of camerashake in a manner similar to that set forth above.

FIGS. 17 and 18 illustrate yet another modification.

FIG. 17, which is an example of an image 88B displayed in the electronicviewfinder 65, corresponds to the diagram at the top of FIG. 9 and toFIGS. 11 and 15. Items shown in the diagram at the top of FIG. 9, etc.,identical with those shown in FIG. 17 are designated by like referencecharacters and need not be described again.

In FIG. 17, the region within the AF target frame 94 is defined as aconfirmation display area 121. The confirmation display area 121 also isformed to have a border 121A. The border 121A may of course be the sameas that of the AF target frame 94. A portion of the image of a subjectcaptured by the solid-state electronic image sensing device 34 isdisplayed in the confirmation display area 121.

FIG. 18 corresponds to FIG. 10, 12 or 16 and illustrates an imageobtained by superimposing the image 88B, which is displayed in theelectronic viewfinder 65 shown in FIG. 17, upon the optical image 85 ofthe subject formed via the objective window 3.

In the confirmation display area 121, which corresponds to the regionwithin the AF target frame 94, the portion of the image of the subjectdisplayed in the electronic viewfinder 65 and captured by thesolid-state electronic image sensing device 34 is superimposed upon theoptical image 85 of the subject. If the image within the confirmationdisplay area 121 is blurry, the user can tell that camera shake istaking place. Since the user decides the camera angle so as to bring adesired principal subject into correspondence with the AF target frame94 and also views the image within the AF target frame 94, the user cantell spontaneously whether the image within the confirmation displayarea 121 is out of focus. Without being aware of it, the user is able torecognize whether camera shake is taking place.

FIGS. 19 and 20 illustrate a further modification.

FIG. 19, which is an example of an image 88C displayed in the electronicviewfinder 65, corresponds to the diagram at the top of FIG. 9 and toFIGS. 11, 15 and 17. Items shown in the diagram at the top of FIG. 9,etc., identical with those shown in FIG. 19 are designated by likereference characters and need not be described again.

In FIG. 19, a comparatively small confirmation display area 131 having aborder 131A has been defined. Further, in the image 88C shown in FIG.19, a camera-shake icon 132 indicating the presence of camera shake isbeing displayed within the visual-field frame 90 at the lower rightthereof. Thus, it may be arranged so that, in a case where camera shakehas been detected by the camera-shake detection circuit 55, an icon orthe like indicating the presence of camera shake is displayed. It goeswithout saying that a portion of the image of the subject captured bythe solid-state electronic image sensing device 34 is displayed withinthe confirmation display area 131.

FIG. 20 corresponds to FIG. 10, 12, 16 or 18 and illustrates an imageobtained by superimposing the image 88C, which is displayed in theelectronic viewfinder 65 shown in FIG. 19, upon the optical image 85 ofthe subject formed via the objective window 3.

In the confirmation display area 131, the portion of the image of thesubject displayed in the electronic viewfinder 65 and captured by thesolid-state electronic image sensing device 34 is superimposed upon istaking place, the image within the confirmation display area 131 will beout of focus and, as described above, the camera-shake icon 132 will bedisplayed. The user can ascertain the presence of camera shake bychecking the camera-shake icon 132.

In the foregoing embodiments, an audio tone may be used to notify theuser if camera shake is taking place. In such case the digital camera 1would be provided with a speaker.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

What is claimed is:
 1. A camera comprising: an optical viewfinder formedon the front of the camera and having an objective window facing asubject and an eyepiece window for looking at the subject seen throughthe objective window; a solid-state electronic image sensing device forimaging the subject and outputting image data representing the image ofthe subject; a display unit for displaying a portion of the image of thesubject, which is represented by the image data that has been outputfrom said solid-state electronic image sensing device, on a displayscreen; a deflecting unit for introducing the portion of the image ofthe subject, which is being displayed on the display screen of saiddisplay unit, to the eyepiece window so as to be superimposed upon thesubject seen through the eyepiece window; a camera-shake detectiondevice for detecting shaking of the camera; and a camera-shakenotification device for notifying of camera shake in response to thefact that camera shake has been detected by said camera-shake detectiondevice, wherein said display unit displays a portion of the subjectimage on the display screen in such a manner that a principal subjectseen through said optical viewfinder and a principal subject image amongsubject images captured in said solid-state electronic image sensingdevice will coincide, and wherein said camera-shake notification devicenotifies of camera shake by displaying, on the display screen of saiddisplay unit, a character string to the effect that camera shake istaking place or an image representing the fact that camera shake istaking place, or by changing the form of a border, which encloses aportion of the image of the subject, in accordance with whether or notcamera shake is taking place.
 2. The camera according to claim 1,wherein if the distance from the camera to a principal subject is equalto or greater than a predetermined distance, said display unit displaysa portion of the subject image on the display screen upon applying aparallax correction in such a manner that a principal subject seenthrough said optical viewfinder and a principal subject image amongsubject images captured in said solid-state electronic image sensingdevice will coincide.
 3. The camera according to claim 1, furthercomprising a recording control device for recording image data, whichhas been output from said solid-state electronic image sensing device,on a recording medium.
 4. A method of controlling operation of a camerawhich includes an optical viewfinder formed on the front of the cameraand having an objective window facing a subject and an eyepiece windowfor looking at the subject seen through the objective window, saidmethod comprising steps of: a solid-state electronic image sensingdevice imaging the subject and outputting image data representing theimage of the subject; a display unit displaying a portion of the imageof the subject, which is represented by the image data that has beenoutput from the solid-state electronic image sensing device, on adisplay screen; a deflecting unit introducing the portion of the imageof the subject, which is being displayed on the display screen of thedisplay unit, to the eyepiece window so as to be superimposed upon thesubject seen through the eyepiece window; a camera-shake detectiondevice detecting shaking of the camera; and a camera-shake notificationdevice notifying of camera shake in response to the fact that camerashake has been detected by said camera-shake detection device, whereinsaid display unit displays a portion of the subject image on the displayscreen in such a manner that a principal subject seen through saidoptical viewfinder and a principal subject image among subject imagescaptured in said solid-state electronic image sensing device willcoincide, and said camera-shake notification device notifies of camerashake by displaying, on the display screen of said display unit, acharacter string to the effect that camera shake is taking place or animage representing the fact that camera shake is taking place, or bychanging the form of a border, which encloses a portion of the image ofthe subject, in accordance with whether or not camera shake is takingplace.